protocols. We begin by defining relationships among routers. From there, we
will move on to defining terms relating to OSPF operations.
ning an OSPF process with the adjacent interface assigned to the same
area. Neighbors are found via Hello packets. No routing information is
exchanged with neighbors unless adjacencies are formed.
router and its corresponding designated routers and backup designated
routers. The formation of this type of relationship depends heavily on the
type of network that connects the OSPF routers.
any given network. Within OSPF, link is synonymous with interface.
interface is added to the OSPF process, it is considered by OSPF as a link.
If the interface is up, then the link is up. OSPF uses this association to
build its link database.
data packet containing link-state and routing information that is shared
among OSPF routers.
OSPF router is connected to a broadcast (multi-access) network. To min-
imize the number of adjacencies formed, a DR is chosen to disseminate/
receive routing information to/from the remaining routers on the broad-
cast network or link.
standby for the DR on broadcast (multi-access) links. The BDR receives
all routing updates from OSPF adjacent routers but does not flood LSA
updates.
Areas are used to establish a hierarchical network. OSPF uses four types
of areas, all of which will be discussed later in this chapter.